[From Graham Butler April 9, 2010]
I have modified the test fixture and done some initial testing with non-locking gas springs (because that is what we can get quickly)
I have attached a series of pictures showing the current state. With 2 riders.... me at 130lbs and Josey at 245 lbs. It turns out the the adjustment system works pretty well. It allows us to adjust the force without changing the shock; but the lift characteristics are not ideal. There are several reasons for this..... the geometry of the test fixture is slightly different from the CAD model. What this means is that we are loosing mechanical advantage in low rider mode, so it is hard to morph up.
Josey in low rider mode.
Note that gas shocks meet the upper linkage arm about 2 1/2 inches from the upper rear joint. Notice later that the meeting position is changed for Graham.
The tester uses two separate adjusters, one for each gas shock. On the finished machine, a single adjuster will move both shocks.
Graham in high rider. Notice how much further back the gas shocks hit the upper linkage arm.